Pivoted armature and actuating member assembly



Dec. 26, 1961 D. F. WILLCOX PIVOTED ARMATURE AND ACTUATING MEMBER ASSEMBLY Filed Jan. 12, 1960 INVENTOR. flaZeFWZZeax, BY

Patented Dec. 26, 1961 3,015,046 PIVOTED ARMATURE AND ACTUATING MEMBER ASSEMBLY Dale F. Willcox, Aurora, 111., assignor to Furnas Electric Company, Batavia, 111., a corporation of Delaware Filed Jan. '12, 1960, Ser. No. 2,037 4 Claims. (Cl. 317-465) The invention relates to switch assemblies for controlling electrical equipment such as electric motors and the like, and has reference in particular to a new and improved pivot connection for releasably joining certain connecting members to the movable armature of the assembly.

Motor starters such as shown in the patents to Furnas et 211., 2,687,502, granted August 24, 1954, and White, 2,855,548, granted October 7, 1958, include a stationary field piece and a movable armature both preferably formed of ferrous laminations and wherein a plastic encased solenoid coil is associated with the field piece for magnetizing the same to cause movement of the armature. One or more connecting members join the movable armature to a contact assembly and thus energization of the solenoid will effect movement of the armature and also the contact assembly to cause the latter to close certain electrical circuits. The connecting members are generally considered as providing a pusher plate for the movable contact assembly. The preferred construction is to extend the pusher plate through a cored opening provided in the plastic encased solenoid, and thus the pusher plate additionally facilitates in the mounting of the armature and contact assembly for free reciprocating movement.

The main objective of the present invention is to provide an improved pivot connection for releasably joining pusher plate structure to a movable armature and which will permit easy and rapid disconnection of the parts for repair or replacement.

Another object of the invention is to provide a pivot connection for releasably joining a movable armature to a pusher plate and which will permit of limited movement of the armature with respect to the pusher plate so that the best coaction of the armature with its field piece will result for the most efficient operations of the switch assembly.

A more particular object of the invention is to provide a pivot connection for an armature and pusher plate as herein described and which will permit limited pivotal movement of the armature for properly seating the armature when it contacts its stationary field piece.

A further object of the invention resides in the provision of a new and novel pivot connection especially adapted for joining a movable armature to a pusher plate and wherein the parts of the pivot assembly are retained in operative relation by a releasable clip preferably formed from a flexible strip of metal.

With these and various other objects in view, the invention may consist of certain novel features of construction and operation, as will be more fully described and particularly pointed out in the specification, drawings and claims appended thereto.

In the drawings which illustrate an embodiment of the device and wherein like reference characters are used to designate like parts FIGURE 1 is a plan view showing those elements of a magnetic switch assembly involved in the present invention and which include a movable armature having a pivoted connection to pusher plate structure all as disclosed in said figure;

FlGURE 2 is a side elevational view showing the complete pivot connection and which illustrates the manner of using a resilient clip for releasably retaining the parts in operative relation;

FIGURE 3 is a plan view of a connecting member of the type adapted to be joined to the armature of a switch assembly;

FIGURE 4 is a side elevational view of the connecting member of FIGURE 3, the same having a pivot bushing affixed thereto;

FIGURE 5 is a front elevational view of a resilient clip which may be employed in the present pivot connection;

FIGURE 6 is a side view of the resilient clip of FIG- URE 5;

FIGURE 7 is a side view of a modified form of resilient clip such as may be employed for releasably retaining the parts of the present pivot connection in operative relation;

FL'GURE 8 is a front elevational view of the resilient clip of FIGURE 7; and,

FIGURE 9 is a view of a pivot pin such as may be employed in the present device.

Referring to the drawings and particularly to FIGURE 1, the electromagnetic structure for a switch assembly of the type as previously referred to consists of a field piece 10 shown in dotted lines, and a movable armature 11 shown in full lines. The parts are generally formed of ferrous laminations and which are secured together by the rivets 12 for form respective rigid, compact units. The field piece has an outline in plan, as shown, and said unit includes a bridging portion 13 for the pole pieces 14, and a central stem 15 having approximately the same length as the pole pieces. The armature 11 is also provided with a pair of pole pieces 18 and a central projection 20 for coaction, respectively, with the pole pieces 14 and the central stem 15 of the field piece. Referring again to the pole pieces 18, it will be noted that the same are provided with shading coils 21 as is conventional in devices of this kind and a solenoid coil, not shown, is associated with the magnet structure by having encircling relation with the central stem 15 and the center projection 20. Upon energization of the coil, the armature 11 will be attracted to the stationary field piece 10 due to the magnetization of the field piece.

The movement of the armature is employed to actuate a movable contact assembly and obviously some form of connecting member must be provided for joining the armature to the contact assembly. The members 23 and 24, FIGURE 2, are typical of the members which in assembled relation provide the pusher plate for the contact assembly. Openings 25 are formed in the right hand end of each member for receiving screws which fixedly secure the members to the contact assembly or to whatever element is to be actuated by the armature. The left hand end of each connecting member is formed with an opening 26 and with lateral recesses 27. The opening 26 is adapted to receive a bushing of plastic material such as nylon or Teflon. Bushing 28 is located in opening 26 of member 23 and the flange 29 of said bushing is located on the undersurface of .the member to provide a stop for properly locating the bushing within the opening. A similar bushing 30 is located in opening 26 of member 24, and the flange 29 similarly positions said bushing with respect to its member. Whereas bushing 28 projects from the top surface of member 23, it will be noted that bushing 30 depends downwardly from member 24. A

cored opening 31 extends completely through each bushing and the diameter of the said opening is such as to receive the metal pin 32 with a tight fit, it being understood that the armature 11 is formed with a passage extending completely through the same and which has a diameter just slightly larger than pin 32 so as to freely receive the pin.

In assembling the parts of the present pivot connec tion it will be noted that the flanges 29 of the respective bushings 28 and 30 are located in contact with the armature 11. Member 23 and bushing 28 are located on top of the said armature and in spaced relation above the stationary field piece 19, Whereas member 24 and bushing 3t) are located below these parts. When the cored openings in the bushings are properly aligned with the passage through the armature 11, the pin 32 can be inserted for pivotally connecting the parts. The top end of the pin is undercut or slightly notched as at 33 for receiving a snap ring 34 or the like which functions to maintain the pivot pin in place and in operative association with the respective pivot bushings.

The pivot connection of the invention is completed by a resilient clip which may be formed from flexible strip material, preferably metal. As best shown in FIGURES 5 and 6 the resilient clip 35 may take the form of a bifurcated member having depending legs 36 and 37 and a connecting portion 38. The bifurcated legs 36 and 37 are bent and have approximately a right angle relation with the portion 38. Also, the legs are bowed or arced as shown in FIGURE 6, so that full use can be made of the inherent flexibility of the clip. At the lower depending end of the legs the same are bent at 46 in the same direction as portion 38, but only to a slight extent sufiicient to provide a latching efifect whereby to maintain the clip in connected and operative relation. As will be understood from FIGURES 2 and 3, the clip 35 is associated with the connecting members and with the armature 11 by locating the bifurcated legs 36 and 37 within the lateral recesses 27. When the portion 38 engages the top of the pin 3'3, the bent end 49 will extend below the member 24. Thus by reason of the bow 37 formed in the clip, the vertex functions as a detent to maintain the resilient clip in place.

Another form of resilient clip for the present pivot connection is shown in *IGURES 7 and 8. The said clip generally identified by numeral 32 includes the bifurcated leg portions 43 and 44, and which depend from a top connecting portion 45. The said legs are spaced from each other and the same are also spaced from a central depending tongue 46 which is bent intermediate its length to form the detent 47. Each leg at its lower depending end is bent at 43 in the same direction as the top connecting portion 45, but only to a slight extent, and just sufficient to assist in maintaining the clip 42 in place, When said clip is operatively associated with the members 23 and 24 and with the armature 11, the legs 43 and 44 have location in the lateral recesses 27 of said member and the detent 47 will have latched over the right hand end of the top member 23. In a so .iewhat similar manner the bent end 48 will be located beyond member 24, and accordingly the clip will be held in place although it is relatively easy for the operator to remove the clip and to disassemble the parts of the pivot connection for either repair or replacement.

The invention is not to be limited to or by details of construction of the particular embodiment thereof illustrated by the drawings, as various other forms of the device will, of course, be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

What is claimed is:

1. In electro-magnetic switch structure, the combination with a stationary field piece, of a movable armature positioned for ccaction with said field piece, a pusher plate assembly, means including a pivot pin for pivotally securing the pusher plate assembly to the movable armature, said pusher plate assembly including a pair of plate members located respectively adjacent opposite surfaces of the armature, and a resilient clip having resilient securement to the pair of spaced plate members for releasably maintaining the members in connected and operative relation. I i

2. in electro-magnetic switch structure, the combination with a stationary field piece, of a movable armature positioned for movement to and from contact with the field piece, a pusher plate assembly including a plate member located adjacent one surface of the armature an second plate member positioned adjacent the other surface of the armature, a pivot pin extending tirough the first plate member, the armature and the second plate member for pivotally connecting the parts, and a resilient clip having resilient connecting relation with the plate members for releasably maintaining the members in operative relation with the armature, said resilient clip permitting pivotal movement of the armature with respect to the plate members to a limited extent, whereby to facilitate proper contact of the armature with the field piece.

3. In electro-magnetic switch structure, the combination with a stationary field piece, of a movable armature positioned for movement to and from contact with the field piece, a pusher plate assembly including a plate member located adjacent the top surface and a second plate member located adjacent the bottom surface of the armature, a pivot pin extending through the first plate member, the armature and the second plate member for pivotally connecting the parts, a bushing carried by each plate member for journalling the pivot pin, a resilient c ip for maintaining the plate members in operative relation with the armature, said clip having a pair of spaced legs and said plate members each having a pair of lateral recesses adapted to receive the legs for resiliently and releasably connecting the plate members, and said resilient clip permitting pivotal movement of the armature with respect to the plate members to a limited extent, whereby to facilitate proper contact and seating of the armature against the field piece.

4. Elcctro-magnetic switch structure as defined by claim 3, wherein the bushing carri d by each plate member is formed of plastic material and includes an annular flange for spacing each plate member with respect to its adjacent surface of the armature, and wherein the resilient clip has a formation which effects a latching of the clip with the plate members when the legs of the clip are located in the lateral recesses.

References Cited in the rile of this patent UNITED STATES PATENTS 

